Shaft packing and seal for centrifugal compressors.



C. E. LITTLE.

SHAFT PACKING AND SEAL Fon CENTRIFUGAL coMPREssoRs.

, APPLICATION FILED MAR.18| 1915. 1,188,189. Patented June 20, 1916.

Inventor: Clar-ence E. Little,

Witnesses:

UNITED l s ATEs PATENT orricn CLARENCE E. LITTLE, or LYNN, MASSACHUSETTS, As'sIGNon." To GENERAL ELECTRIC. COMPANY, AvconronATIoN or NEW Yonx. v

SHAFT PACKING AND sEAL'FoaCENTBIFUGAL CoMrnEssons.

Speci'cation of Letters Patent. Patented June 20, 1916.

Application filed March 18, 1915. Seriallo. 15,170. Y

To all whom it may concern: Be it known that I, CLARENCE E.'L1TTLE,

a citizen ofthe United States, residing at` Lynn, county of Essex, State -of Massachusetts, have invented certain new and useful Improvements in Shaft, Packings and Seals Vfor Centrifugal Compressors, of which the plosive'or offensive gases, as for `example illuminating' gas, where it is desirable'that there shall be no leakage of gas to the atmosphereor of atmosphere to the gas, although it is not limited thereto.

Y The object of the invention is to provideV an improved arrangement for this purpose.

' The accompanying drawing is a diagrammatic view, partly in section, illustrating an embodiment of my invention.

Referring to the drawing, 2 indicates a centrifugal compressor of any approved type having the shaft 3, inlet conduit 4f and discharge conduit 5. It may be, for example, a gas booster and under such circumstances the admission pressure may be about atmospheric pressure or slightly above, and the discharge pressure about 6 lbs. gage. It will be understood, of course, that these values are only by way of illustration.

The packing and seal for the shaft on the inlet or low pressure side of the compressor comprises a casing 6 surrounding the shaft and suitably connected to the casing of the compressor.. It is providedl with a plurality of partition members 7 forming an intermediate chamber 8 surrounding the shaft, and one or more chambers 9 on each side thereof. In the present instance I have shown one chamber 9 on each side. The chamber Sis connected with a suitable source of uid pressure, as water pressure, by way of conduit 10, and this pressure in the chamber may be regulated by the valve 11.l 12 is a pressure gage for indicating the pressure therein. Each of the chambers 9 is provided with a drain pipe 13 connecting with a. waste pipe 14, the drain pipe connecting with the chamber 9 adjacent the compressor casing being provided with a reverse bend forming a trap 15 to prevent the escape of gas. This chamber may also be provided with a small impeller or fan 16, if

found desirable, for creating a pressure therein tending to prevent leakage from the casing of the compressor to such chamber. TheA edges of the partitions v7 which surround the shaft are provided with serra-tions or grooves 17 which form a labyrinth packing to prevent leakage.

The packing and seal on the discharge side of the compressor is the same as that on the inlet side except that an' additional chamber 18 is provided which is connected to the inlet side of the compressor by a pipe 19.l .This maintains chamber 18 at about the land seal is the same as lthat already described the same reference numerals have been applied to corresponding parts'.

In operation the valves 11 will be adjusted so that the water pressure in'cliambers 8 will be slightly above the pressures existing in the adjacent chambers 9. This means that there will be a tendency for water to How from chambers 8 in both directions through the labyrinth packings thusforming a seal which on the one hand prevents air. from leaking through to the compressor casing and on the other hand prevents gas leaking to atmosphere. The' water which passes through the packings to chambers 9 is thrown off from the shaft by centrifugal force and escapes by way of the drain pipes 13. The water in the leg of trap 15 prevents any gas escaping to the waste pipe as will be readily understood.

In accordance with the provisions of the same pressure as that on the inlet side of the machine, and conducts any leakage frompatent statutes, I have described the princile of operation of my invention,'together ith the apparatus which I now consider to represent the best embodiment thereof:

tions forming a labyrinth packing for the shaft, a pipe connected with the intermediate chamber for supplying a fluid under pressure thereto, and drain pipes connected with the remaining chambers, the drain pipe connected With the chamber next to the compressor casing being-provided with a reverse bend forming a trap to prevent the escape of gas or vapor therefrom.

2. The combination with a centrifugal compressor, of a packing and seal for the shaft on the discharge side thereof, comprising a casing surrounding the shaft, partitions therein forming a plurality of chambers, a pipe connecting a chamber adjacent the compressor casingoto the inlet side of the compressor, said pipe having an unrestricted passage through it so that the pressure in said chamber will be that on the inlet side of the compressor, and means for supplying a fluid under pressure to an intermediate ehamber. v

3. The combination. with a centrifugal compressor, of a packing and seal for the shaft thereof, comprising a casing surrounding the shaft and attached to the cour presser casing, partitions in the casing forming an intermediate chamber and a chamber on each side thereof, a pipe for supplying Water under pressure to the intermediate chamber, and drain pipes connected with the other chambers, the drain.

pipe connected with the chamber next to the compressor casing being provided with a reverse bend forming a trap to prevent the escape of gas or vapor therefrom.

4. The combination with a centrifugal compressor, of a packing and seal therefor, comprising a casing surrounding the shaft, partitions therein forming a plurality of annular chanibers, a pipe connecting the chamber adjacent the4 compressor. casingl to the inlet side of the compressor, said pipe having an unrestricted passage through it so that the pressure in said chamber will be that on the inlet side of the compressor, and a pipe supplying fluid under pressure to an intermediate chamber.

In witness whereof, I have hereunto set my hand this 16th day of March, 1915.

A CLARENCE E. LITTLE.

"Witnesses:

JOHN A.. MCMANUS, Jr.,

JOHN F. BEEQHLYN. 

